The "Jieshi" refers to Jieshi Mountain, located in Qinhuangdao, Hebei. This sentence comes from Cao Cao's "Guan Cang Hai", which was composed by Cao Cao after his victory in the northern expedition to Wuhuan. The Wuhuan were a nomadic people in the north who had good relations with the Yuan family during the Three Kingdoms period. After Yuan Shao's death, Cao Cao gradually eliminated the Yuan family's power. The two brothers Yuan Shang and Yuan Xi, who were outmatched, had no choice but to flee to Wuhuan for refuge. After that, Wuhuan frequently sent troops to attack the people on the border. Cao Cao felt very troubled by this, so he finally decided to personally lead his army to conquer Wuhuan to avoid future troubles.
When Cao Cao's army approached its lair, Wuhuan realized it, so he hurriedly sent two brothers, Yuan Shang, and tens of thousands of troops to resist. At that time, most of Wuhuan's cavalry were cavalry, and the Wuhuan cavalry, who were nomadic people, were already strong, so Cao's army was defeated steadily for a while. However, it didn't take long for Cao Cao to discover that although Wuhuan's army was strong, its formation was very chaotic, so he adjusted his offensive strategy accordingly, thus completely changing the battlefield situation. In the end, Cao's army won a complete victory, Wuhuan suffered numerous casualties, and even Chanyu was beheaded.
At that time, the Wuhuan national army was distributed in three places. After the battle, Cao Cao launched attacks on the remaining two places one after another. In the end, they all won, and the remaining forces of the Yuan family were all eliminated. After winning the battle, Cao Cao set off to return to the court with his troops. On his way back, he passed a place called "Jieshi Mountain". After Cao Cao climbed the mountain, he saw the vast sea. After experiencing the victory, he was inspired to write the poem "Landing the Jieshi in the East to View the Sea".
In fact, there is not only one place named "Jieshi" in the northern region, but three. The reason why it is believed that the Jieshi mentioned in "Guan Cang Hai" is the Jieshi Mountain in Qinhuangdao is a judgment made by later scholars based on relevant evidence. One of the evidences is the relevant cultural relics unearthed from the tomb of Meng Jiangnu. The second basis is that "Langtaosha Beidaihe" written by Mao Zedong also mentioned "Eastern Jieshi".